desktop: place kernel in the live layer

Placing the kernel in the live layer allows for selecting at install
time which kernel to install.

live-build/auto/config

@@ -716,7 +716,6 @@ case $PROJECT in
 			*)
 				touch config/universe-enabled
 				PASSES_TO_LAYERS="true"
-				KERNEL_FLAVOURS='generic-hwe-22.04'
 				# the standard layer, contains all base common packages for later layers
 				add_task standard minimal standard ubuntu-desktop ubuntu-desktop-default-languages
 				add_package standard cloud-init
@@ -724,6 +723,7 @@ case $PROJECT in
 				add_task standard.live ubuntu-live
 				remove_package standard.live ubiquity-frontend-gtk
 				add_snap standard.live ubuntu-desktop-installer/classic
+				add_package standard.live linux-generic-hwe-22.04 casper
 				# the enhanced-secureboot layer, contains all packages for the enhanced secureboot install
 				add_package standard.enhanced-secureboot cryptsetup boot-managed-by-snapd
 
@@ -1183,7 +1183,7 @@ case "$ARCH${SUBARCH:++$SUBARCH}" in
 esac
 
 case $PROJECT:${SUBPROJECT:-} in
-	ubuntu-server:*|ubuntu-base:*|ubuntu-oci:*)
+	ubuntu-server:*|ubuntu-base:*|ubuntu-oci:*|ubuntu:)
 		OPTS="${OPTS:+$OPTS }--linux-packages=none --initramfs=none"
 		KERNEL_FLAVOURS=none
 		BINARY_REMOVE_LINUX=false

live-build/ubuntu/hooks/020-ubuntu-live.binary

@@ -0,0 +1,26 @@
+#! /bin/sh
+
+# Kernels are deliberately installed into the live layer for Subiquity
+# installers. This provides the ability to select a different kernel later, a
+# key function for OEM support and a general capability for Subiquity.
+
+set -eux
+
+case ${PASS:-} in
+    standard.live)
+        ;;
+    *)
+        exit 0
+        ;;
+esac
+
+if [ -n "${SUBPROJECT:-}" ]; then
+    echo "We don't run Ubuntu Desktop hooks for this project."
+fi
+
+. config/binary
+. config/functions
+
+mv chroot/boot/initrd.img-* ${PWD}/livecd.${PROJECT}.initrd-generic-hwe
+mv chroot/boot/vmlinu?-* ${PWD}/livecd.${PROJECT}.kernel-generic-hwe
+chmod a+r ${PWD}/livecd.${PROJECT}.initrd-generic-hwe ${PWD}/livecd.${PROJECT}.kernel-generic-hwe